In such systems, a symmetric leveling laser beam, which may sweep, or scan, or be directed along a desired path, is caused by optical means in a portable target to be separated into at least two focused images. Displacement of the target relative to the incoming beam causes the images to be unequal. When the target is on the optical center of the beam the images are equivalent Prior inventions assigned to the same assignee as this application typically use a lens function for focusing the incoming light, an axicon function for separating the beam into at least two parts, and a diffusing surface, e.g. a screen, for viewing the images. This invention incorporates the same optical functions into a more easily manufactured optical structure.